Evaporation apparatus

ABSTRACT

An evaporation apparatus proposed includes a gas storage chamber, a first evaporator, a pressure gauge, a pyrolysis chamber and a deposition chamber. The first evaporator is connected with the gas storage chamber through a first pipe and the first pipe has a first valve. The pressure gauge is connected with the gas storage chamber through a second pipe. The pyrolysis chamber is connected with the gas storage chamber through a third pipe and the third pipe has a second valve, wherein the first evaporator is connected with the pyrolysis chamber through the gas storage chamber, and the gas storage chamber is disposed between the first evaporator and the pyrolysis chamber. The deposition chamber is connected with the pyrolysis chamber through a fourth pipe.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. application Ser.No. 13/337,317, filed on Dec. 27, 2011, which claims the prioritybenefit of Taiwan application serial no. 100136277, filed on Oct. 6,2011. The entirety of each of the above-mentioned patent applications ishereby incorporated by reference herein and made a part ofspecification.

TECHNICAL FIELD

The disclosure relates to an evaporation apparatus and a method offorming an organic film.

BACKGROUND

Organic film has superior capability in water resistance and gasresistance, high transparency, better in electrical insulation, inpreventing rust, corrosion, and efflorescence. Thus, the organic film isusually adopted as the gas barrier layer which is foamed on the surfaceof the flexible substrate in current flexible displays. Moreover, theorganic film is also adopted as the release layer for the flexibledisplay.

In conventional fabrication, an organic film is generally formed by achemical vapor deposition (CVD) method. Taking a parylene film as anexample, powdered parylene is placed in an evaporator and heated toabout 150° C. for evaporating powdered parylene. Parylene gas is thenpassed to a pyrolysis chamber and heated to about 650° C. for pyrolysis.Next, parylene monomer is delivered to a deposition chamber anddeposited on a substrate.

However, since organic material is likely to heat unevenly in theevaporator, the evaporated organic material is not able to pass to thepyrolysis chamber stably and continuously. Accordingly, the organic filmformed by deposition may have a non-uniform thickness, andreproducibility of the organic films is not manufacturale.

SUMMARY

The disclosure demonstrates an evaporation apparatus design which iscapable of depositing material stably.

In the disclosure, an evaporation apparatus is designed. The evaporationapparatus includes a gas storage chamber, a first evaporator, a pressuregauge, a pyrolysis chamber, and a deposition chamber. The firstevaporator is connected with the gas storage chamber through a firstpipe, where the first pipe has a first valve. The pressure gauge isconnected with the gas storage chamber through a second pipe. Thepyrolysis chamber is connected with the gas storage chamber through athird pipe, where the third pipe has a second valve, wherein the firstevaporator is connected with the pyrolysis chamber through the gasstorage chamber, and the gas storage chamber is disposed between thefirst evaporator and the pyrolysis chamber. The deposition chamber isconnected with the pyrolysis chamber through a fourth pipe.

Accordingly, in the disclosure, when the pressure of the gas in the gasstorage chamber reaches the predetermined value, that is, a specificamount of the gas is stored in the gas storage chamber, the gas is thenpassed to the subsequent chamber for deposition. Therefore, the gasstorage chamber is able to supply the gas stably for continuousdeposition process, and the thickness uniformity of the film andreproducibility of the films are good.

Several exemplary embodiments accompanied with figures are described indetail below to further describe the disclosure in details.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the disclosure, and are incorporated in and constitutea part of this specification. The drawings illustrate exemplaryembodiments of the disclosure and, together with the description, serveto explain the principles of the disclosure.

FIG. 1 is a schematic view of an evaporation apparatus according to oneembodiment of the disclosure.

FIG. 2 is a flowchart illustrating a method of forming an organic filmby using an evaporation apparatus of the disclosure.

FIG. 3 is a schematic view of an evaporation apparatus according toanother embodiment of the disclosure.

DESCRIPTION OF EMBODIMENTS

FIG. 1 is a schematic view of an evaporation apparatus according to oneembodiment of the disclosure. Referring to FIG. 1, an evaporationapparatus 100 includes a gas storage chamber 102, a first evaporator104, a pressure gauge 106, a pyrolysis chamber 108, and a depositionchamber 110. The gas storage chamber 102 is configured to store areactive gas which is delivered from the first evaporator 104. The firstevaporator 104 is connected with the gas storage chamber 102 through afirst pipe 112, where the first pipe 112 has a first valve 114. Thefirst evaporator 104 is configured to evaporate a material to form thereactive gas, which is then passed into the gas storage chamber 102. Thefirst valve 114 is configured to control whether or not to pass thereactive gas generated in the first evaporator 104 into the gas storagechamber 102. In an embodiment, the first evaporator 104 is disposed witha material container therein to contain the material to be evaporated.

The pressure gauge 106 is connected with the gas storage chamber 102through a second pipe 116. The pressure gauge 106 is configured tomeasure the pressure of the gas in the gas storage chamber 102. Thepyrolysis chamber 108 is connected with the gas storage chamber 102through a third pipe 118, where the third pipe 118 has a second valve120. The pyrolysis chamber 108 is configured to perform a pyrolysis tothe reactive gas which is delivered from the gas storage chamber 102.The second valve 120 is configured to control whether or not to pass thereactive gas stored in the gas storage chamber 102 into the pyrolysischamber 108. The deposition chamber 110 is connected with the pyrolysischamber 108 through a fourth pipe 122. The deposition chamber 110 isconfigured to deposit the reactive gas delivered from the pyrolysischamber 108 by a chemical deposition process, for example, so as to forma film on a substrate to be deposited in the deposition chamber 110. Thefirst and second valve 114, 120 are, for example, an air actuated valve,respectively.

Furthermore, the evaporation apparatus 100 includes a pressure adjustingvalve 124 connected with the gas storage chamber 102 through a fifthpipe 126. The pressure adjusting valve 124 is configured to pass apressure adjusting gas into the gas storage chamber 102, so as to adjustthe pressure of the gas in the gas storage chamber 102. In particular,since the evaporated reactive gas is likely to deposit when thetemperature of the environment is lower than its evaporationtemperature, the evaporation apparatus 100 usually includes a constanttemperature maintaining device (not shown), so that the evaporatedreactive gas may be maintained in an evaporation state. In anembodiment, the evaporation apparatus 100 further includes a supply lineof carrier gas connected with the gas storage chamber 102 through a pipe(not shown). The supply line of carrier gas is configured to supply thecarrier gas for carrying the reactive gas in the gas storage chamber 102to the pyrolysis chamber 108 through the third pipe 118. In anembodiment, the evaporation apparatus 100 further includes a supportingdevice (not shown), which is configured to dispose a substrate in thedeposition chamber 110.

In the evaporation apparatus 100, the gas storage chamber 102 isconnected with the first evaporator 104 and the pyrolysis chamber 108through the first pipes 112 and the third pipe 118, respectively. Thefirst pipes 112 and the third pipe 118 are controlled by the first andsecond valve 114, 120, respectively, for passing the reactive gas.Particularly, the first and second valve 114, 120 are electricallyconnected to the pressure gauge 106, and the turning on and off thefirst and second valve 114, 120 may be controlled according to thepressure of the gas in the gas storage chamber 102, respectively. Indetail, when the pressure of the gas in the gas storage chamber 102,measured by the pressure gauge 106, does not reach a predeterminedvalue, the second valve 120 may be turned off for preventing thereactive gas from passing into the pyrolysis chamber 108, and the firstvalve 114 may be turned on for passing the reactive gas into the gasstorage chamber 102. According to the ideal gas equation PV=nRT, as thepressure P (which is the predetermined value herein), the volume V, thetemperature T are constant, the pressure of the gas in the gas storagechamber 102 does not reach the predetermined value described above meansthe amount of the gas is not equal to a specific value. Therefore, thefirst valve 114 is turned on for passing the reactive gas into the gasstorage chamber 102.

Moreover, when the pressure of the gas in the gas storage chamber 102,measured by the pressure gauge 106, reaches the predetermined value,that is, the amount of the gas is equal to a specific value, the firstvalve 114 may be turned off, and the second valve 120 may be turning onfor passing the reactive gas into the pyrolysis chamber 108 forpyrolysis. Since the reactive gas is passed into the pyrolysis chamber108 with the specific amount, continuous deposition process may beperformed. Therefore, the film is formed with nice thickness uniformityand reproducibility of the multiple films is good. Particularly, thethickness of the film deposited on the substrate can be adjusted throughsimply setting the predetermined pressure of the reactive gas by theoperator, and the film has nice thickness uniformity.

In the following, the embodiment, in which an organic film is depositedby using the evaporation apparatus 100, is provided for illustrationpurpose and is not construed to limiting the present disclosure.

FIG. 2 is a flowchart illustrating a method of forming an organic filmby using an evaporation apparatus of the disclosure. Referring to FIGS.1 and 2, in step 200, an organic material is placed in the firstevaporator 104, the second valve 120 which is connected with thepyrolysis chamber 108 is turned off, and the first valve 114 which isconnected with the gas storage chamber 102 is turned on. The organicmaterial is, for example, in powder form. In the present embodiment, theorganic material is parylene powder, for instance. Alternatively, theorganic material is, for example, in liquid form, such as parylene,hexamethyldisilane (HMDS), hexamethyldisiloxane (HMDSO),hexamethyldisilazane (HMDSN), tetramethylsilane (TMS), tetraethylorthosilicate (TEOS).

In step 202, an evaporation process is performed to the organic materialin the first evaporator 104, so as to form an organic gas. In thebeginning of the evaporation process, the evaporation rate of theorganic material is not steady because the temperature of the firstevaporator 104 is increased to the evaporation temperature of theorganic material (i.e. about 150° C. when the organic material isparylene) from the room temperature. However, in the present embodiment,before the amount of the gas formed in the evaporation process is equalto a specific value, the gas is stored in the gas storage chamber 102,rather than immediately delivered to the pyrolysis chamber 108.Therefore, the subsequent deposition process is not affected by unsteadyevaporation rate of the organic material.

In step 204, when the pressure of the organic gas in the gas storagechamber 102, measured by the pressure gauge 106, reaches thepredetermined value, the first valve 114 is turned off and the secondvalve 120 is turned on for passing the organic gas into the pyrolysischamber 108 through the third pipe 118. In other words, thepredetermined value is set by the operator, and according to the idealgas equation PV=nRT, the amount of the gas in the gas storage chamber102 is equal to a specific value when the pressure of the organic gas inthe gas storage chamber 102 reaches the predetermined value. At thismoment, the organic gas is delivered to the pyrolysis chamber 108. In anembodiment, the temperature of the gas storage chamber 102 can bebetween 50° C. and 300° C., and the predetermined pressure can bebetween 50 mtorr and 1000 mtorr. Particularly, in an embodiment, whenthe pressure of the organic gas in the gas storage chamber 102, measuredby the pressure gauge 106, does not reach the predetermined value, thepressure adjusting valve 124 is turned on for passing a pressureadjusting gas into the gas storage chamber 102 through the fifth pipe126. The pressure adjusting gas is, for example, an inert gas, such asargon, helium, or nitrogen.

In step 206, the organic gas is pyrolyzed in the pyrolysis chamber 108to form an organic monomer.

In step 208, the organic monomer is delivered to the deposition chamber110 through the fourth pipe 122 for deposition, so as to form an organicfilm in the deposition chamber 110. In an embodiment, the organic filmis formed, for example, on a substrate in the deposition chamber 110,and the substrate may be disposed on the supporting device (not shown)in the deposition chamber 110.

FIG. 3 is a schematic view of an evaporation apparatus according toanother embodiment of the disclosure. In FIG. 3, the same referencenumbers are used to refer to the same parts in FIG. 1, and thedescription for these parts is omitted. Referring to FIG. 3, thedifference between the evaporation apparatus 100 and the evaporationapparatus 300 lies in the evaporation apparatus 300 further includes asecond evaporator 302. The second evaporator 302 is connected with thegas storage chamber 102 through a sixth pipe 304, where the sixth pipe304 has a third valve 306. The third valve 306 is configured to controlwhether or not to pass the gas generated in the second evaporator 302 tothe gas storage chamber 102. The third valve 306 is, for example, an airactuated valve.

During the deposition process performed by the evaporation apparatus300, when the material in the first evaporator 104 has been consumed,the first valve 114 can be turned off and the material in the secondevaporator 302 is immediately used to generate the organic gas forreplacing the material in the first evaporator 104. Therefore, thedeposition process can be performed continuously.

In an embodiment, during the deposition process performed by theevaporation apparatus 300, before evaporating the first organic materialin the first evaporator 104, the third valve 306 is turned off forpreventing the gas passing into the second evaporator 302. That is, whenan evaporation process is performed in the first evaporator 104, thesecond valve 120 is turned off and the first valve 114 is turned onwhile the third valve 306 is turned off. A first evaporation process isperformed to the first organic material in the first evaporator 104 andthe formed first organic gas is then passed into the gas storage chamber102 through the first pipe 112. When the pressure of the first organicgas in the gas storage chamber 102, measured by the pressure gauge 106,reaches the predetermined value, the first valve 114 is turned off andthe second valve 120 is turned on for passing the first organic gas intothe pyrolysis chamber 108 through the third pipe 118. The first organicgas is pyrolyzed in the pyrolysis chamber 108 to form a first organicmonomer, and the first organic monomer is then delivered to thedeposition chamber 110 through the fourth pipe 122 for deposition, so asto form a first organic film in the deposition chamber 110. After thefirst organic material in the first evaporator 104 has been consumed,the first valve 114 is turned off, and a second organic material isplaced in the second evaporator 302 while the third valve 306 is turnedon. A second evaporation process is performed to the second organicmaterial in the second evaporator 302, so as to form a second organicgas. Similarly, the third valve 306 is turned on for passing the secondorganic gas into the gas storage chamber 102 through the sixth pipe 304before the pressure of the second organic gas in the gas storage chamber102 reaches the predetermined value. When the pressure of the secondorganic gas in the gas storage chamber 102 reaches the predeterminedvalue, the third valve 306 is turned off, and the second valve 120 isturned on for passing the second organic gas into the pyrolysis chamber108 through the third pipe 118. After that, the second organic gas ispyrolyzed in the pyrolysis chamber 108 to form a second organic monomer,and the second organic monomer is delivered to the deposition chamber110 through the fourth pipe 122 for deposition, so as to form a secondorganic film on the substrate disposed in the deposition chamber 110. Ingeneral, the second organic material is the same as the first organicmaterial and can be the organic materials illustrated in theaforementioned embodiment.

In the present embodiment, the evaporation apparatus 300 includes twoevaporators, and therefore the second evaporator 302 can be used toperform the chemical deposition process when the material in the firstevaporator 104 has been consumed. Meanwhile, the material can berefilled in the first evaporator 104. Similarly, when the material inthe second evaporator 302 has been consumed, the first evaporator 104with refilled material is used. As a consequence, the continuousfabrication can be achieved by alternately using the evaporators withoutstopping the apparatus to supplement the materials. It is noted that inother embodiment, the evaporation apparatus can optionally include morethan two evaporators disposed therein. Furthermore, the evaporationapparatus described in aforementioned embodiments is suitable forfabricating a release layer, a gas barrier layer or other devices in amanufacturing process of a flexible display, a flexible solar cell and afilm package.

In the conventional forming method of the organic film, the organicmaterial is heated and evaporated in the evaporator, and the evaporationrate of the organic material is not steady because the material isheated unevenly and the volume change of the material is not linear.Therefore, the evaporation rate of the organic material is decreased asthe amount of the organic material is decreased, which results insignificant difference (such as 15% to 20%) in thickness between thefilms. In other words, reproducibility of the films fabricated in thedeposition process is poor. However, in the aforementioned embodiment,the gas is passed from the gas storage chamber into the subsequentchamber for deposition after a specific amount of the gas is stored inthe gas storage chamber. Therefore, the gas storage chamber is able tosupply the gas stably for continuous deposition process, and the formedfilm has nice thickness uniformity. Moreover, reproducibility of thefilms in thickness is good, such as the difference in thickness betweenthe films is lower than 5%.

In summary, the evaporation apparatus of the disclosure includes the gasstorage chamber, the pressure gauge, the first valve, and the secondvalve. The gas storage chamber is configured to store the reactive gasdelivered from the evaporator, and the pressure gauge is configured tomeasure the pressure of the gas in the gas storage chamber. The firstvalve is configured to control whether or not to pass the gas generatedin the evaporator to the gas storage chamber, and the second valve isconfigured to control whether or not to pass the gas stored in the gasstorage chamber to the pyrolysis chamber. When the pressure of the gasin the gas storage chamber reaches the predetermined value, the gas ispassed into the subsequent chamber for deposition by turning off thefirst valve and turning on the second valve. Therefore, the gas storagechamber is able to supply the gas stably for continuous depositionprocess, the formed film has nice thickness uniformity, andreproducibility of the films in thickness is good. Moreover, bydisposing a plurality of the evaporators in the evaporation apparatusand using the evaporators alternately, the continuous fabrication can beachieved without stopping the apparatus to supplement the materials.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of thedisclosed embodiments without departing from the scope or spirit of thedisclosure. In view of the foregoing, it is intended that the disclosurecover modifications and variations of this disclosure provided they fallwithin the scope of the following claims and their equivalents.

What is claimed is:
 1. An evaporation apparatus, comprising: a gasstorage chamber; a first evaporator, connected with the gas storagechamber through a first pipe, wherein the first pipe has a first valve;a pressure gauge, connected with the gas storage chamber through asecond pipe; a pyrolysis chamber, connected with the gas storage chamberthrough a third pipe, wherein the third pipe has a second valve, whereinthe first evaporator is connected with the pyrolysis chamber through thegas storage chamber, and the gas storage chamber is disposed between thefirst evaporator and the pyrolysis chamber; and a deposition chamber,connected with the pyrolysis chamber through a fourth pipe.
 2. Theevaporation apparatus as claimed in claim 1, further comprises apressure adjusting valve connected with the gas storage chamber througha fifth pipe.
 3. The evaporation apparatus as claimed in claim 1,further comprises a second evaporator connected with the gas storagechamber through a sixth pipe, wherein the sixth pipe has a third valve.